Surgical Helmet System Including a Garment With A Face Shield and a Method of Regulating the System

ABSTRACT

A surgical helmet system and a method of regulating the system. The system including a helmet and garment. The helmet comprising a module, a sensor, and a control processor. The control processor in communication with the module and the sensor, and is configured to selectively energize the module based on an input from the sensor. The garment comprises a face shield and is configured to be removably secured to the helmet so that the face shield is positioned forward of the helmet. The method comprises a measuring a temperature and selectively energizing the module based on the measured temperature. The method may further comprise selectively energizing the module for a time period that is proportional to a difference between a measured temperature and a desired temperature.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is divisional of U.S. patent application Ser.No. 15/761,363, filed on Mar. 19, 2018, which is a National Stage ofInternational Patent Application No. PCT/US2016/052491, filed on Sep.19, 2016, which claims priority to and all the benefits of U.S.Provisional Patent Application No. 62/221,266, filed on Sep. 21, 2015,all of which are hereby expressly incorporated herein by reference intheir entirety.

FIELD OF THE INVENTION

This invention generally relates to a personal protection system such asthe type of personal protection system worn by a healthcare provider.The personal protection system of this invention includes a coolingstrip that draws heat away from the individual wearing the system.

BACKGROUND OF THE INVENTION

During some medical and surgical procedures, a healthcare provider willwear an assembly known as a personal protection system. This type ofassembly includes a helmet. A protective garment is placed over thehelmet to, at a minimum, cover the head of the wearer. A garment thatonly extends a short distance below the head is sometimes referred to asa hood. A garment that extends to the waist or even below the waist isreferred to as a gown or a toga. Regardless of the length, the garmentincludes a transparent face shield. The fabric forming the garmentprovides a barrier between the healthcare provider and the ambientenvironment. The face shield is a transparent part of this barrier thatprovides a view of the location at which the procedure is beingperformed.

The barrier benefits both the patient and the healthcare provider. Thebarrier substantially eliminates the likelihood that the healthcareprovider may come into contact with fluid or solid bits of matter fromthe patient that may be generated during the course of the procedure.Also, a healthcare provider, like any individual, invariably emitsmicroscopic and near microscopic sized dead skin cells, perspirationdroplets and saliva. The barrier provided by the personal protectionsystem substantially eliminates the possibility this material will landon the normally concealed tissue of the patient that is exposed in orderto perform the procedure. The limiting of the extent to which thepatient's internal tissue is exposed to this material results in a likereduction in the likelihood that the material will induce an infectionin tissue.

If an individual simply wears a garment over the head, an inevitableresult of that individual's breathing would be the build up of carbondioxide and water vapor under the garment. No one, especially ahealthcare worker performing a procedure, wants to be subjected to theharmful effects of excessive exposure to carbon dioxide. If water vaporis allowed to build up inside the garment, the vapor could condenseagainst the inside surface of the face shield. The formation of thesewater droplets can reduce the visibility through the face shield.

To avoid the undesirable results of carbon dioxide and water vapor frombuilding up under the garment of a personal protection system, a fan ismounted to the helmet of the personal protection system. The fan drawsair into the space under the garment, the space around the head of theperson wearing the system. This air forces the carbon dioxide and watervapor laden air away from around the head of the individual wearing thesystem. Examples of such systems are described in U.S. Pat. No.6,481,019/PCT Pub. No. WO 2001/052675 and U.S. Pat. No. 7,735,156/PCTPub. No. WO 2007/011646 each of which is incorporated herein byreference. Present personal protection systems both provide a barrieraround an individual wearing the system and prevent the undesirablebuild of carbon dioxide and water vapor under the garment.

Nevertheless, an individual wearing a personal protection system, likeany individual, generates heat. This heat warms the air immediatelyadjacent the individual. When an individual is not wearing a personalprotection system, the heat in the air immediately adjacent theindividual is transported away from the individual by the convectivemovement of the air away from the individual as well as by theconduction of the heat into the air parcels spaced away from theindividual. When an individual wears a personal protection system, thegarment restricts the flow of air away from the individual. While thefan circulates air through the garment, the resultant convective andconductive transport of the heat away from the air surrounding theindividual is less than what occurs when the garment is not worn.

Consequently, when some individuals wear a personal protection system,the air around these individuals can become uncomfortably warm.Surgeons, in particular, are known to consider being encased in apersonal protection garment a less than desirable experience. This isbecause a surgeon, in response to feeling stress during a procedure, maygenerate more heat than an individual who does not have the surgeon'sresponsibility. The generation of this relatively large quantity of heatcan result in the environment inside the personal protection garmentbecoming unpleasant.

In theory, it is possible to reduce the build up of warm air inside apersonal protection garment by increasing the rate of flow of airthrough the garment. This would require providing the system with a fancapable of producing this type of air flow. One disadvantage of thistype of system is that a providing the system with a large fan typicallyresults in providing the system with a fan that emits an appreciableamount of noise. The added noise pollution this type of fan cancontribute to an operating room inherently makes it more difficult forthe individuals wearing the personal protection system to communicate.Further, this added noise pollution adds to the distractions theindividuals performing the procedure have to ignore to concentrate onthe procedure. Another disadvantage of providing a personal protectionsystem with a fan with larger air flow capabilities than fans currentlyused is that this fan draws more power than the power drawn by thecurrent fans. Typically, the power is provided to personal protectionsystem fan by a battery. If the power draw of the fan is increased thereis an increased likelihood that, during the procedure, system batterywill be completely drained. If the individual wearing the system wantsto continue to use the system, this would require interrupting theprocedure in order to replace the battery.

Another solution has been proposed regarding how to keep an individualwearing a personal protection system cool. This solution involvesplacing Peltier modules inside the helmet of a personal protectionsystem. A Peltier module, sometimes referred to as a thermoelectriccooling module, is a laminate structure that has a ceramic superstrateand an opposed ceramic substrate. Sandwiched between the superstrate andsubstrate are semiconducting components. Conductors flow the electricitythrough the semiconducting components. The current flow through thesemiconducting components fosters the transport of thermal energybetween opposed surfaces of the module. One surface becomes a heat sink.The opposed surface becomes a heat source. An inherent feature of asurface that functions as a heat source is that the surface draws heat,thermal energy, away from what surrounds the surface. Thus, the surfaceof a Peltier module that is the heat source functions as cooling platesince that surface draws heat away from an object in contact with thesurface.

It has therefore been proposed that one or more Peltier modules could bemounted inside the helmet of a personal protection system. The moduleswould be mounted to the helmet so the heat source surfaces of themodules press against the skin of the individual wearing the system.When the system is activated, current is flowed through the Peltiermodules. The Peltier modules would draw heat away from the skin againstwhich the modules abut. The drawing away of this heat would help keepthe temperature of the individual wearing the system within a desirablerange.

There are, however, disadvantages of simply providing the helmet ofpersonal protection system with one or more skin abutting Peltiermodules. One disadvantage of this type assembly is that when a Peltiermodule is activated, the heat source surface draws thermal energy awayfrom the surface of the object immediately in contact with the module.This means that when a module is simply in contact with the skin, mostof the heat loss is from the skin immediately in contact with themodule. As a result, the individual wearing the helmet can feel as ifonly localized portions of his/her body are being kept cool. Thisfeeling is analogues to what a person feels when the skin is cooled byplacing ice cubes at spaced apart locations on the skin. The differencein skin temperature between where the cooling is occurring and adjacentsection where the cooling is not occurring can be substantial. Thisdifference can be disconcerting to the person wearing the personalprotection system.

Further when the application of current to a Peltier module isterminated there may be a significant amount of thermal energy adjacentthe module. For example, this thermal energy may be stored in a heatsink adjacent the surface of the module spaced from the individualagainst which this module is pressed. As a result of the deactivation ofthe Peltier module, this thermal energy can flow back to the surface ofthe module pressed against the individual. This thermal energy can flowinto the skin the person against which the Peltier module is pressed.When this event occurs, the individual wearing this cooling unit,instead of being cooled by the Peltier modules, is heated.

Further some individuals that use a personal protection system may notwant the system to include Peltier modules. For example, during aprocedure an individual participating in the procedure, owing to his/herpersonal physiology, may not need the added cooling the Peltier modulescan provide under the garment. This individual may even be irritated byhaving to wear a helmet that includes the added weight of the Peltiermodules. In theory, a surgical facility could resolve this problem byproviding some helmets with Peltier modules and other helmets withoutthese modules. However, unless a relatively large number of both typesof helmets are provided, it may be difficult to, for a procedure, haveenough of both types of helmets to ensure that preferences of eachindividual participating in the procedure is met.

SUMMARY OF THE INVENTION

This invention is related to a new and useful personal protection systemsuch as the type of system used to provide a sterile barrier betweenmedical personal and a patient. The personal protection system of thisinvention is designed for use by both individuals that would enjoyhaving heat removed by the Peltier modules and individuals that wouldprefer not having to wear a system that includes these modules. For theindividual that would enjoy the added cooling providing by the Peltiermodules the invention is constructed to ensure that the draw of heataway from the individual is over an area wider than the surface of themodules. For the individual that does not need to have to wear a helmetwith these modules, this invention provides a simple means to easilyremove the modules from the garment support structure to which themodules are attached. In many versions of the invention, this garmentsupport is a helmet.

The personal protection system of this invention includes a componentthat is worn around the head of the individual using the system. In manyversions of this invention, this component is a helmet that is worn onthe head. The helmet supports a garment that, at a minimum, extends overthe head of the individual. The helmet typically, but not always,includes a fan for drawing air from the ambient environment into thegarment so the air flows around the head of the individual.

The personal protection system of this invention includes one or morecooling strips. Each cooling strip includes at least one Peltier module.Mounted to the Peltier module is a heat sink. The heat sink performs twofunctions. The heat sink functions as a thermally conductive member witha larger surface area over which the heat drawn into the Peltier moduleis conductively diffused into the surrounding environment. A secondfunction of the heat sink is to releasably secure the cooling module tothe helmet to which the cooling strip is mounted.

In many preferred versions of the invention, the cooling strip includesplural Peltier modules. In these versions of the invention, the coolingmodule is typically designed so that the Peltier modules are spacedapart from each other. The cooling strip is further constructed so thatthe surfaces of the Peltier modules that are the heat absorbing(cooling) surfaces are attached to a common draw strip. The draw stripis formed from thermally conductive material. The opposed surfaces, theheat discharging surfaces, of the Peltier modules are disposed against abiasing element. These biasing elements place a force on the Peltiermodules that push the draw strip against the skin of the individualwearing the personal protection system. In some versions of theinvention, a single foam strip functions as the set of these biasingelements.

A further feature of this invention is that control unit that regulatesthe actuation of the at least one Peltier module does not, when thecooling strip is to be turned off, simply completely negate theapplication of current to the module. Instead after the cooling strip isdeactivated, the control unit, cyclically applies current to the atleast one module. The current is applied until the at least one modulereaches a temperature at which the backflow of any heat will not resultin a rise in module temperature that could possible result in thediscomforting heating of the individual wearing the cooling strip.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is pointed out with particularity in the claims. The aboveand further features and benefits of this invention may be understood bythe following Detailed Description taken in conjunction with theaccompanying drawing in which:

FIG. 1 is a perspective view of a personal protection system constructedin accordance with this invention;

FIG. 2 is a perspective view of the headband of the helmet of thisinvention with a cooling strip attached;

FIG. 3 is a is perspective view of the headband without the coolingstrip attached;

FIG. 4 is a perspective view of the cooling strip wherein the exposedsurface of the cooling strip is seen.

FIG. 5 is a exploded view of the cooling strip;

FIG. 6 is a plan view of how a Peltier module is mounted to the flexstrip;

FIG. 7 is a perspective view of a heat sink; and

FIG. 8 is a second perspective view of a heat sink.

FIG. 9 is a perspective view of the inner foam layer of the coolingstrip;

FIG. 10 is a plan view of the back side of the inner foam layer of thecooling strip;

FIG. 10 is a perspective view of a heat sink; and

FIG. 11 is a block diagram of the circuit used to source current to thePeltier modules; and

FIGS. 12A and 12B collectively form a flow chart of the steps that occurwhen the cooling strip of the personal protection system of thisinvention is actuated.

DETAILED DESCRIPTION

A personal protection system 30 constructed in accordance with thisinvention, as seen in FIG. 1, includes a garment 32, shown in dashedlines, that is disposed over a helmet 50. The garment 32 is formed frommaterial that forms a sterile barrier between the individual wearing thesystem 30 and the outside environment. Garment 32 is shaped to have ahood section 34 shaped to extend over the complementary helmet 50. Thegarment 32 typically includes at least a shoulder section 36 that isintegral with and extends below the hood section 34. As implied by itsname, the shoulder section extends around the shoulder of theindividual. If the garment does not extend below the shoulder, thegarment is typically referred to as a hood. Some garments extend belowthe shoulder. These garments typically have sleeves for receiving thearms of the individual. This type of garment is sometimes referred to asa toga.

The garment hood section 34 is formed with an opening, (opening notidentified). A transparent face shield 38 is mounted to the garment toextend over the hood section opening. The face shield 38 is the portionof the garment through which the wearer is able to view the surroundingenvironment.

Helmet 50, seen in FIGS. 1 and 2, and 3, includes a headband 52. A fanmodule 54 is disposed above the headband 52. The fan module 54 includesa fan, (not illustrated). The fan internal to the fan module 54 drawsair through the overlying hood section 34 of the garment 32. A frontnozzle 60 is attached to the front of the headband 52. (Here, “front”and “forward” are understood to mean in a direction directed outwardlyfrom the face of individually wearing system 30. “Back” and “rear” areunderstood to mean in a directed opposite the front direction.) A rearnozzle 64 is mounted to the back of the headband. Front bellows 58connects the fan module 54 to the front nozzle 60. Rear bellows 62connects the fan module to the rear nozzle 64. When the fan module 54 isactuated, a fraction of the air drawn into the module by the fan isforced through the front bellows 58 and discharged out the front nozzle60. The remaining air drawn into the fan module 54 is forced through therear bellows 62 and discharged from the rear nozzle 64.

A chin bar 66, also part of the helmet 50, extends below the frontportion of the head band 52. The front portion of the head band 52 it isunderstood to be the portion of the head band worn around the foreheadof the individual wearing the personal protection system 30. The chinbar 66 includes two spaced apart posts 70. Posts 70 extend downwardlyforwardly outwardly from opposed ends of the forehead section of theheadband 52. A beam 72 extends between the free ends of posts 70. Helmet50 is shaped so that between posts 70, beam 72 curves outwardly. Onefunction chin bar 66 has is to prevent the face shield 38 fromcollapsing inwardly towards the faces of the individual wearing thesystem. This reduces the feeling of claustrophobia some individuals havewhen wearing a hood 34 with a face shield 38 around the head. Beam 92also defines the radius of curvature of the lower portion of the faceshield 38.

The system 30 of this invention also includes components for ensuringthe garment face shield 38 is centered in front of the face of theindividual wearing the system. In the described version of theinvention, one of these features is a tab 76 that protrudes upwardlyfrom the front nozzle 60. The helmet 50 is also provided with twomagnets 78, one magnet seen in FIG. 1, that also are part of the holdingassembly. Each magnet 78 is mounted to a separate one of the posts 70.The magnets 78 are mounted to posts 70 a short distance, approximately 2cm, above the beam 72.

While not illustrated, garment 32 is provided with complementaryfeatures for releasably holding the face shield 38 in the properposition relative to the helmet 50. These features include an opening inthe top of a portion of the face shield. This opening is formed in thesection of the face shield that is located inside hood section 34. Twomagnetic elements are also mounted to the face shield 38. Collectively,the opening is located and the face shield magnetic elements arepositioned so that when helmet tab 76 seats in the opening, the faceshield can be flexed around the chin bar beam 72 so the face shieldmagnets can mate with the helmet magnets 78. As a consequence of thehelmet tab 76 seating in the face shield opening and the two sets ofmagnets engaging, the garment 32 is releasably secured to the helmet 50so the face shield 38 is located in front of the helmet.

Also part of system 30 of this invention is a cooling strip 120, seen inFIG. 2. The cooling strip 120 is attached to the inner surface of theheadband 52. When the cooling strip 120 is actuated, the strip drawsthermal energy, heat, away from the individual wearing the system 30.

The headband 52, seen best in FIG. 3, is formed from a flexible plasticsuch as nylon or polypropylene or

PEEK plastic. The headband 52 includes a number of different sections.One of these sections is the previously described forehead section 90.Side sections 92 extend from the opposed ends of the forehead section.Each side section 92 is curved in shape. The curves in the side sections92 facilitate fitting the side sections above the ears of the individualwearing the helmet 50. A tail 94 extends from the free end of each sidesection 92. In the illustrated version of the invention a strap 98extends upwardly from the center of the forehead section. Strap 98supports the fan module 54.

Headband 52 is further formed so there are pairs of through slots 102 inthe forehead section 90 (two slots identified). Slots 102 are parallelto the opposed top and bottom edges of the forehead section 90. Thetop-located slots 102 are collinear. The bottom-located slots 102 arelikewise collinear.

Each tail 94 is formed with an oval shaped opening 104 (one openingidentified). The headband is formed so the tails 94 have teeth 106 thatextend into the openings 104 (two teeth identified). When the helmet 50is assembly the headband is wrapped around itself so the tails 94overlap. The rear nozzle 64 is mounted to the tails 94. Componentsintegral with rear nozzle not illustrated and not part of the presentinvention hold engage the teeth 106 and hold the tails 94 together todefine the closed loop of the headband that seats around the head of theindividual. These components allow the length of the sections of thetails 94 that overlap to be selectively set. This allows the size of theloop defined by the headband to be adjusted based on the size of thehead of the individual wearing the helmet 50.

Not identified are a number of circular openings formed in the headband.These openings are surrounded by raised sections of the headband, raisedsections also not identified. These openings receive fasteners 108, onefastener identified in FIG. 1, hold the front nozzle 60 and chin bar 66to the headband.

The cooling strip 120, now described by reference to FIGS. 4 and 5,includes a number of Peltier modules 150, (one module identified).Sometimes a Peltier module is referred to as a thermoelectric coolingmodule. Each Peltier module 150 includes on one side a heat absorbingsurface 152 (one identified). The opposed side of Peltier module is aheat discharging surface 158, (the edge of one heat discharging surfaceidentified. Not seen are the semiconducting elements internal to thePeltier modules 150. When current is flowed through the semiconductingelements, the charge carriers transfer heat from the component of themodule that forms the heat-absorbing surface 152 to the component thatforms the heat-discharging surface 158. Two leads 156 extend from eachPeltier module 150 as seen in FIG. 6. The leads 156 are the conductorsover which current is flowed through the Peltier module 150.

The Peltier modules 150 are mounted to a flex strip 162, also part ofthe cooling strip 120. Flex strip 162 is formed from a flexible materialsuch as copper or polyimide. Conductors 164, one identified in FIG. 5,are formed on or embedded in the flex strip 162. Conductors 164 are theconductive components of the cooling strip 120 over which current issourced through leads 156 to the Peltier modules 150.

The flex strip 162 is formed with plural spaced apart windows 166, twowindows identified. Each Peltier module 150 is seated in a separate oneof the windows 164. As seen in FIG. 6, epoxy 167, that is applied aroundthe side surfaces of the Peltier module and over the portion of the flexcircuit that defines the window in which the module is seated, holds thePeltier module in the window. FIG. 6 also illustrates how the leads 156integral with the Peltier module are soldered to the conductors 164.

The Peltier modules 150 have a front to back thickness that isapproximately 2 to 4 mm greater than thickness in the same dimension asthe flex strip 162. The Peltier modules 150 are mounted to the flexstrip so the heat discharging surfaces 158 are located forward of thefront facing surface of the flex strip 162 and the heat absorbingsurfaces are located rearward of the back facing surface.

Two temperature sensors are mounted to the flex strip 162. A firsttemperature sensor 148 is mounted to the flex strip 162 to be able tomonitor the temperature of the heat absorbing surface 152 of one of thePeltier modules 150. In FIG. 5 the temperature sensor 148 is shown asbeing physically disposed over the heat absorbing surface 152 of thePeltier module with which the sensor is associated. A second temperaturesensor, sensor 168, is also mounted to the flex strip so as to extendrearward from the flex strip 162. Temperature sensor 168 is shownmounted to the flex strip 162 so as to be spaced away from the Peltiermodules 150.

Heat sinks 170, two identified, are attached to Peltier modules 150. Aheat sink 170, seen best in FIGS. 7 and 8, is formed from a metal withgood thermal conductive properties, for example material having athermal resistance no greater than 20 C./W and, more preferably, nogreater than 18° C./W. Each heat sink 170 includes a planar base 172.The components forming the cooling strip are typically dimensioned sothat the heat sink base 172 has a surface area that is typically atminimum at least equal to the surface area of the heat dischargingsurface of the associated Peltier module 150. Fins 174 projectperpendicularly forward from the opposed sides of the base 172. In thedepicted version of the invention, three fins 174 extend forward fromeach side of the base. Fins 174 have a side-to-side thickness thatallows the fins to seat in the slots 102 internal to the headband.

Ribs 176 extend outwardly from the outer surfaces of fins 174. In thedepicted version of the invention, each rib 176 extends across the threefins 174 that extend from each side of the of the heat sink base 172.The ribs are located forward of the base. Each rib 176 has a rearwardlyfacing surface 178. Rearward facing surface 178 extends perpendicularlyoutwardly from the fins with which the rib is associated. A front facingsurface 180 extends forward from the rearward facing surface 178. Thefront facing surface has a concave profile. As surface 180 extendsforward, the surface curves inwardly. The front facing surface 180merges into the planar outer side surface of the fins 174 with which therib 176 is integral.

An adhesive able to maintain a bond when exposed to temperatures ofbetween 5 and 50° C. and that is thermally conductive is used to holdthe base of each heat sink 172 to the heat discharging surface 158 ofthe associated Peltier module. Here, thermally conductive is understoodto mean having a thermal conductivity greater than 1 W/m-K. One suchadhesive that can be employed as this adhesive is a metallic silverepoxy. One such epoxy is the MX-3 epoxy sold by the Arctic SilverCompany of Switzerland.

An inner flexible foam layer 186 is disposed over the front facingsurface of flex strip 162 and the front facing surfaces of the bases 172of the heat sinks 170. Foam layer 186 is a foam such as a visco-elasticfoam. Foam layer 186 has a perimeter that is identical to the perimeterof flex strip 162. Foam layer 186, described in detail with respect toFIGS. 9 and 10, is formed with plural spaced apart recesses 188, tworecesses identified. The recesses 188 extend inwardly from therearwardly directed surface of the layer. Each recess 188 is shaped toreceive the base 172 of a separate one of the heat sinks 170. Foam layer186 is also formed to have a number of through slots 190. Each throughslot 190 extends from the portions of the foam layer that forms the baseof a recess 188 and extends through the foam layer. Two slots 190 extendforward from each recess 188. The slots 190 forming each pair of slotsextend inwardly from the opposed sides of the recess 188 with which theslots are associated.

Upon assembly of the cooling strip 120, the inner foam layer 186 isseated against the forward facing surface of the flex strip 162 so thatportions of the Peltier modules that extend forward from the flex stripand the heat sink bases seat in the recesses 188. The heat sink fins 174extend forward through the slots 190.

An outer foam layer, layer 134, is disposed over the front facingsurface of flex strip 140. The outer foam layer 134, which is flexible,is formed from a material such as visco-elastic foam or spacer knitfabric. Foam layer 134 is shaped to have an outer perimeter that issubstantially identical to the outer perimeter of the flex strip 162.Foam layer 134 is formed to have a number of spaced apart windows 136,two windows identified. Windows 136 extend front to back through thelayer 136. Foam layer 134 is formed so that when the cooling strip isassembled, the section of each Peltier module that extends rearward fromthe flex strip seats in a separate one of the windows 136.

Outer foam layer 134 is further formed to have a through opening 138.The opening 138 is located between two of the windows 136. Moreparticularly, the cooling strip 120 is constructed so that temperaturesensor 168 seats in foam layer opening 134.

The components forming the cooling strip 120 are further selected sothat the rearward directed surface of the outer foam layer is eitherflush with or extends rearwardly outwardly from the heat absorbingsurfaces 152 of the Peltier modules 150 and the heat sensitive surfaceof temperature sensor 168.

Cooling strip 120 of this invention also includes a draw strip 128. Drawstrip 128 is secured to and extends over the exposed rearwardly directedface of outer foam layer 134. Draw strip 128 is also disposed over andbonded to the exposed heat absorbing surfaces 152 of the Peltier modules150 and temperature sensor 168. Draw strip 152 it should thus beappreciated extends outwardly beyond the heat absorbing surfaces 152 ofthe Peltier modules 150. The draw strip 128 is formed from flexiblestrip of material that has thickness typically no greater than 1 mm. Thematerial forming the draw strip is also material that highly thermallyconductive. Typically the thermal conductivity of the draw strip isgreater than the thermal conductivity of the headband. In many versionsof the invention, the draw strip has thermal conductivity of at least100 W/mK, typically at least 400 W/mK and, more preferably, at least 700W/mK. In some versions of the invention the draw strip 128 is formedfrom a laminate that has copper substrate and polyester superstrate. Onesuch example is the PH3 heat spreader available from T-Global TechnologyCo., Taoyuan City, Taiwan. Other laminates with high thermalconductivity are formed from PGS graphite.

An adhesive, not illustrated, holds the draw strip 128 to the heatabsorbing surfaces 152 of the Peltier modules, and the adjacentrearwardly directed surface of the outer foam layer 134. The adhesive isformed from material that has a thermal conductivity of at least 1.2W/mK. The adhesive also holds the draw strip to temperature sensor 168.

FIG. 11 is a schematic and partial block diagram drawing of thecomponents that regulate the application of current to the Peltiermodules 150. These components include a control processor 218. One inputinto the control processor 218 is the signal from an on/off switch 203.The signals from temperature sensors 148 and 168 are also used tocontrol the regulation of the application of current to the Peltiermodules 150. The signal from temperature sensor 148 is applied directlyto the processor 218. In practice, it is understood that the controlprocessor 218 uses a digitized representation of the signal from sensor148 as the input for regulating operation of the Peltier modules 150.Many control processors include internal analog-to-digital convertersthat perform the necessary signal conversion.

The signal from temperature sensor 168 is shown as being applied to oneinput of a comparator 206. The second input into comparator 206 is thesignal present at a wiper of a potentiometer 204. A reference voltageV_(REF) is shown applied to one end of the potentiometer 204. Theopposed end of the potentiometer 204 is shown tied to ground. The outputfrom the comparator 206 is an input signal applied to the controlprocessor 218.

Reference voltage V_(REF) is also shown as being the signal applied tothe control processor 218 when switch 203 is closed. Not shown and notpart of the invention are voltage source that provides the V_(REF)signal.

Control processor 218 functions by selectively connecting a battery 202to the Peltier elements. In FIG. 11 an n-channel FET 220 is shown havingits drain connected to the positive terminal of the battery 202 and itssource connected to the series connected Peltier modules 150. Controlprocessor 218 selectively asserts the gate signals that turns on andturns off the FET 220.

In many constructions of system 30, battery 202 and control processor218 are typically not dedicated components associated with the coolingstrip 120. In many versions of the invention, battery 202 also suppliesthe charge used to activate the fan internal to the fan module 54. Thecontrol processor 218 based on control switch not illustrated and notpart of the invention regulates the application of energization signalsto the fan. In many versions of the invention, the control processor ismounted in the module that contains the cells forming battery 202. Notpart of this invention is how this module is connected to either the fanmodule 54 or the cooling strip 120.

When an individual wants to use the personal protection system withcooling strip of this invention, one step required is to mount thecooling strip 120 to the helmet 50. This step is performed by forcingthe heat sink fins 174 through the slots 102 in the helmet headband 52.One result of this positioning of the heat sinks is the ribs 176 snapthrough the slots 102. Ribs 176 protrude outwardly from the headband 52so the step like rearward facing surfaces 178 of the heat sinks pressesagainst the adjacent front facing surface of the headband 52. The heatsink ribs 176 thus releasably hold the cooling strip 120 to the helmet52.

As a consequence of the dimensioning of the components forming personalprotection system 30, the sections of the inner foam layer 186 betweenthe bases 172 of the heat sinks and the headband 52 are compressed.

The individual wearing the personal protection system places the helmet50 on his/her head. As a result of the adjustment of the headband 52 thedraw strip 128 presses against the forehead of the individual.

The battery and control module are then connected to the fan module 54and cooling strip 120. The garment 32 is placed over the helmet. As partof this step of preparing the system for use, the garment is secured tothe helmet so the face shield 38 is located forward of the helmet.Typically after these last steps are performed, the system 30 of thisinvention for use.

The individual often starts to activate the system by setting theappropriate control member so as to activate the fan.

When the individual wants to use the cooling strip to remove heatgenerated by his or head, the individual closes switch 203, step 230 inFIG. 12A. The individual also sets the potentiometer 204 to indicate theextent to which the individual wants the heat drawn away from his/herbody.

In response to the closing of switch 203, step 232 in FIG. 12A, controlprocessor 218 selectively connects the battery 202 to the Peltiermodules 150, step 232. In some versions of the invention, selectivelygates FET 220 to apply a pulse width modified signal to the Peltiermodules 150. The current applied during this actuation of the Peltiermodules can be considered the cooling state current.

When the cooling strip is actuated, comparator 206 outputs a signal thatrepresents the difference between the measured skin temperature of theindividual wearing the personal protection system 30 as measured bysensor 168 and the skin temperature desired by the user based on thesetting of the potentiometer 204. The control processor 218 adjusts theon duty cycle so that it is proportional to the difference between themeasured skin temperature and the individual desired skin temperature.Thus, in some versions of the invention, the time period of a singlepulse of the cooling state current is between 3 and 20 seconds. Moretopically, the pulse time is between 5 and 15 seconds. The minimum onduty cycle for which the current is sourced during is typically at least25% of the total time period. The maximum on duty cycle is typically 75%of the total time period.

As a result of the current being flowed through the Peltier modules 150,the charge carriers transfer the thermal energy present on the heatabsorbing surfaces 152 of the Peltier modules 150 towards the heatdischarging surfaces 158. The heat absorbing surfaces 152 draws heataway from what is in contact with these surfaces. In the presentinvention, draw strip 128 is what is in contact with the heat absorbingsurfaces 158. Thermal energy, contained in the draw strip 128 and, byextension the skin against which the draw strip is pressed, is drawnthrough the strip to the heat absorbing surfaces 152. The heat istransferred to the heat discharging surfaces 158 of the modules 150.Owing to the thermally conductive properties of the heat sinks 170,thermal energy reaching the heat discharging surfaces is conducted awayfrom these surfaces 158 to the fins 174. The heat is transferred byconduction to the air immediately surrounding the fins 174. The warmedair parcels adjacent the fins 174 move away from the fins to be replacedby parcels that have yet to be heated. The forced movement of these airparcels as a result of the fan drawing new air into the garment 32facilitates this convective transfer of thermal energy away from thefins 174. In this manner the heat extracted from the skin by the coolingstrip of this invention does not build up in the air mass inside thegarment immediately adjacent the person wearing the system.

At some point in the process of the procedure, the individual wearingsystem 30 turns off the cooling strip. The individual performs thisaction by opening switch 203. The loop back from step 234 to step 232represents that, as long as switch 203 remains closed, the processorcontinues to provide current to the Peltier modules 150.

When switch 203 is opened, control processor 218 does not immediatelynegate the application of current to the Peltier modules 150. Instead,in a step 236 applies a backflow prevention current to the Peltiermodules. This backflow prevention current is a current causes at leastsome heat transfer to occur from the heat absorbing surfaces 152 to theheat discharging surfaces 158 of the modules 150. Here “at least someheat transfer” is understood be heat transfer sufficient tosubstantially, if not totally, prevent heat transfer from the heatdischarging surfaces 158 to the heat absorbing surfaces 152. Thebackflow prevention current is also typically at a level that does notresult in the significant sinking of heat from the draw strip 128 to theheat absorbing surfaces 152. In versions of the invention wherein theprocessor only controls the current flow to the Peltier modules 150 byregulating the on duty cycle of the current flow, the on duty cycle whenthe backflow prevention current is applied is typically no greater thanon duty cycle when the cooling strip is set to provide the minimalamount of noticeable cooling. Thus, the backflow prevention current is acurrent that is equal to or less than the cooling state current.

As represented by the loop from step 238 back to step 236, the backflowprevention current is typically applied for a select period of time, acool down period. This time period is often between 2 and 10 minutes.After this time period elapses, the processor 218, in step 240 based onthe signal from sensor 148, determines whether or not the temperature onthe heat absorbing surface 152 of the module to which the sensor isattached is below a threshold temperature. If this evaluation testspositive, then it is unlikely that the final turning off of the coolingstrip will result in the backflow of heat to the module heat absorbingsurfaces that will be noticeable to the individual. Accordingly, if theevaluation of step 240 tests positive, in step 242 the processor totallydeactivates the cooling strip. Thus, in step 242 the processor turns FET220 off so as to completely terminate the sourcing of current to thePeltier modules.

Alternatively, the evaluation of step 240 may test negative. Thisindicates that residual thermal energy stored in the heat sinks couldbackflow to the module heat absorbing surfaces 152 so as to heat thesesurfaces 152 to above an unacceptable temperature. Therefore, if theevaluation of step 240 tests negative, as indicated by the loop back tostep 238 continues to apply a backflow prevention current to themodules. Steps 240 and 242 are reexcuted until the evaluation of step242 indicates the sensed heat absorbing surface temperature is at abelow the selected maximum level.

System 30 is designed so that the cooling strip 120 can be removablyattached to the helmet 50 to which the strip is mounted. This means thatif an individual does not want to use the cooling strip 120 he/she doesnot have to wear a helmet that is weighted down with for this individualis a useless component. If the individual wants to use the coolingstrip, the strip is easily installed by the snap fitting of the heatsinks to the head band 52. In the event a cooling strip malfunctions,the fact that the strip is releasably attached to the helmet makes iteasy to replace with a properly functioning strip.

The system is thus further designed so the heat sinks perform twofunctions. The heat sinks 170 draw the heat away from the Peltiermodules 150. The heat sinks also function as the components thatreleasably hold the cooling strip 120 to the rest of the system.

System 30 of this invention is designed so inner foam layer 186 places abiasing force on the components of the cooling strip located rearward ofthe layer 186 Specifically, the outer foam layer 186 urges the Peltiermodules 150 and the inner foam layer 134 towards the skin of theindividual wearing the system 30. Inner foam layer 134 places a force onthe sections of draw strip 128 between the modules 150 rearwardly,again, towards the individual wearing the system 30. These forces presssubstantially all, if not the whole of, the rear facing surface of thedraw strip 128 against the skin. The draw strip 128 owing to theflexibility of the material forming the strip is compliant against theskin. This strip-against-skin abutment occurs even though the coolingstrip 120 presses against a portion of the patient's anatomy that is notlinear in shape. This means that when the cooling strip 120 is actuated,heat is drawn away from surface of the skin that is contact with thedraw strip 128. This surface area of the portion of the draw strip thatpresses against the skin is at least two times and more often at leastfour times greater than the surface area of the skin covered by thePeltier modules. This means that, when drawing a given amount of heataway from the skin, the amount of heat per unit area over which the heatis drawn away according to this invention is less than if the heat wereonly drawn away from the area underneath the Peltier modules. Thisminimizes the extent to which an individual using this system in orderto feel cool under a head enclosing garment is exposed to thedisconcerting sensation of having heat draw from a few small sections ofhis/her skin.

System 30 of this invention is further constructed so that when thecooling strip 120 is actuated, the Peltier modules 150 are cycled on andoff. The off phases occur during the off duty cycles of the pulse widthmodulated periods. One benefit of so cycling the activation of thePeltier modules 150 is that, providing this off time, the system allowsthe thermal energy already accumulated on the heat sink fins 174 todissipate away from the heat sink 170. This reduces the undesirablybuild up of heat in the air immediately surrounding the heat sink.Further by cycling the Peltier modules 150 off, the draw on the battery202 is reduced.

Moreover, if the heat is continually drawn away from the skin, anindividual may become acclimated to this heat draw. Should an individualbecome so acclimated, he/she feels may feel it necessary to, in order tofeel cool, increase the heat draw away from his/her skin. If anindividual feels the need to increase the heat draw, he/she mustincrease the current flow through the Peltier modules 150. Oneundesirable effect of this action is that it can result in the morerapid discharge of the batteries. Since the batteries are typically thesame batteries used to power the fan, this can increase the likelihoodthat the batteries could completely discharge. If the batteries are sodischarged it may be necessary to interrupt the procedure to provide afreshly battery. Having to so interrupt the procedure can increase theoverall time it takes to perform the procedure.

Thus a further benefit of this system being configured to cyclicallyturn off the Peltier modules 150 when the cooling strip 120 is actuatedis that the modules 150 are not continually in the state in which theydraw large quantities of heat away from the individual wearing thesystem. This reduces the extent to which an individual, over a period oftime, acclimates to the heat draw. This results in like reduction in theextent to which an individual, feeling so acclimated, feels that it isnecessary to increase the current flow to the Peltier modules in orderto obtain their benefit. This reduces the likelihood that theindividual, in order to feel cool, will want to set the current draw tosuch a high level that the battery 202 completely discharges.

System 30 of this invention is further designed so that, upon theturning off of the cooling strip, a backflow prevention current isapplied to the Peltier modules 150 for a period of time. Thissubstantially reduces the likelihood that when the cooling strip 120 isturned off, heat stored in the heat sinks 170 backflow to the heatabsorbing surfaces and the draw strip. Preventing this heat flowessentially eliminates the likelihood that upon the turning off of thecooling strip the individual wearing the system will immediately findhis/her head being heated.

A further feature of this invention is that the flex strip 162 internalto the cooling strip performs two functions. The strip functions as themembrane that supports the conductors that extend to the Peltier modulesand the temperature sensors. The flex strip 162 also functions as thesupport frame to which the outer structural components of the coolingstrip are mounted.

The above is directed to one specific version of the invention. Otherversions of the invention may have features different from what has beendescribed.

For example, not all versions of the invention may have each of theabove-described features. For example not all versions of the inventionmay include each of; the cooling strip; the control system for pulsecontrolling the Peltier modules; the control system for, after turningoff the Peltier modules flowing a backflow prevention current throughthe modules.

In some versions of the invention, it may not be necessary to providethe helmet with a fan. Similarly the cooling strip could be part of apersonal protection system that simply consists of a headband to which aface shield is attached.

Similarly, the structural features of the invention may be differentfrom what has been described. In some versions of the invention theinner foam layer may only be spaced apart foam sections that are locatedforward of the heat discharging surfaces of the Peltier modules. Theouter foam layer may be spaced apart sections of foam disposed betweenthe Peltier modules. In some versions of the invention, one or both ofthe foam layers or similar biasing components may not be necessary.

There is no requirement that in all versions of the invention one morefoam layers function as the biasing members that urge the draw striptoward the skin of the individual against whim the cooling strip isapplied. For example, mechanical springs may take the place of one orboth of the foam layers. One such type of mechanical spring that canperform this function is a wave washer. Alternatively a compressible yetresilient rubber such as a silicone rubber may function as the biasingcomponent. If the compressible resilient material is also highlythermally conductive, this material may be disposed over the heatabsorbing surfaces 152 of the Peltier modules 150. In these versions ofthe invention this resilient material functions both as the flexibledraw strip of the cooling strip and the component that biases the drawstrip against the skin of the individual wearing the personal protectionsystem.

There is no requirement that, in all versions of the invention, thecooling strip 120 be releasably mounted to another component of thepersonal protection system so the draw strip presses against theforehead. In some versions of the invention, the cooling strip 120 maybe mounted to another component of the system to press against the backof the head, the neck, the side of the head or another section of theindividual's anatomy. Likewise, some personal protection systems of thisinvention may be designed so that plural cooling strips can be attachedto the components of the system that hold the garment over theindividual using the system. Thus, given the ability to remove thecooling strips from the other components, typically the helmet, thisfeature of the invention allows further customization of the system foreach individual. For example, for an individual that likes to feel verycool during a procedure, two cooling strips can be attached to thehelmet. One strip is positioned to press against the forehead, thesecond is positioned against the back of the head. The system would havea separate configuration for an individual that only wants the back ofhis/her cooled. For this individual, only the single back locatedcooling strip is attached. Thus this individual receives the benefit ofthe cooling he/she desires without having to wear a version of thesystem that is weighted down by an unused cooling strip.

From the above it should also be clear that, in some versions of theinvention, an assembly other than a helmet may function as thestructural member that supports garment. One such assembly is a bracelike unit that is worn around the shoulders of the individual takingadvantage of the system.

In some versions of the invention, the cooling strip is mounted to thecomplementary component so that the heat sink fins are in the duct ornozzle or immediately downstream of the nozzle opening through which theair from the fan module is discharged. A benefit of this version of theinvention is that the air flow over the heat sinks fins improves theconvective transfer of heat away from the heat sinks over the transferthat occurs when the fins are in static air.

The arrangement of the components forming the draw strip may also varyfrom what has been described. For example, in some versions of theinvention, the Peltier modules 150 may be mounted to the flex strip 162so the heat absorbing surfaces of the modules are disposed against theinner face of the strip. In these versions of the invention the flexstrip is formed from material that has a relatively high thermalconductivity. One such material is copper. In these versions of theinvention the flex strip is therefore not formed with windows. In someembodiments of these versions of the invention the draw strip is securedover the outer face of the flex strip. It should be understood that inthese embodiments of the invention, the draw strip has a thermalconductivity that is greater than the thermal conductivity of the flexstrip. In alternative embodiments of this version of the invention, aseparate draw strip is not affixed to the flex strip. This, in theseembodiments of the invention, the flex strip, in additional toperforming its other functions serves as the draw strip of the coolingstrip.

Likewise, the circuit used to control the sourcing of current to thePeltier modules may also vary from what has been described. That may notbe a need in all versions of the invention to use pulse width modulationto regulate the rate at which the Peltier modules transfer heat awayfrom the skin. In some versions of the invention, this regulation may beperformed by using an adjustable current source to set the level of thecurrent that is sourced through the Peltier modules 150. In someversions of the invention the shift from applying the cooling statecurrent to the backflow prevention current is performed by adjustingboth the on duty cycle and level of current applied to the Peltiermodules. In some versions of the invention, for the application of oneor both of the cooling state current and the backflow prevention currentis regulated by, during a single on-cycle, sequentially applying currentat plural levels to the Peltier modules.

This invention is not limited to assemblies wherein the draw strip ofthe cooling strip is simply a sheet of material or a flexible laminatestructure. In some constructions of the invention, the draw strip mayconsist of a pack filled with phase change material. Phase changematerial is material that, at the appropriate high temperature, hereapproximately 25° C., absorbs heat and turns from solid to liquid. Thenat a lower temperature, here approximately 15° C. or less, releases thestored heat and returns to the solid state. Within the pack the phasechange material circulates from the position adjacent where the outsideenvironment is at a high temperature, the skin of the individual, towhere the outside environment is at a lower temperature, adjacent theheat absorbing surfaces of the Peltier modules 150. The phase changematerial thus transfers the heat away from the sections of the skinbetween the Peltier modules 150 to the Peltier modules.

In some versions of the invention, current flow through the Peltiermodules may be controlled by both pulse width modulation and byregulating the level of the current flow. Thus, during the time in whichthe cooling strip is actuated, the current at first high level issourced to the modules 150. Pulse width modulation is used to regulatethe sourcing of this current so as to regulate the rate at which themodules draw heat away from the skin. Once the cooling strip 120 isdeactivated, a low level current is continually applied to the modules.This low level current is the backflow prevention current applied to themodules 120 to prevent the undesirable backflow of thermal energy to theheat absorbing surfaces 152 of the modules.

In versions of the invention where the heat sinks also function ascomponents that removably hold the cooling strip to the supportstructure, the heat sinks may not always snap into openings in thesupport structure. For example the heat sinks may be flexible clips. Theclip portions of the heat sinks fit over complementary beam linksections of the support structure.

In some versions of the invention some or all of the actuatable controlmembers used to turn on/turn off/set the cooling strip 120 as well asthe circuit that regulates the sourcing of the current to the Peltiermodules are built into the cooling strip. Often one or more of thesecomponents are mounted to the flex strip. A benefit of this constructionof this invention is that it avoids the expense of adding thesecomponents to each personal protection system to which the cooling stripmay or may not be attached.

In some versions of the invention a temperature sensor may be mounted toone or more of the heat sinks 170. The signal from this temperaturesensor is used to determine whether or not it is still necessary toprovide the backflow prevention current. More specifically, if thistemperature sensor indicates that the temperature of the heat sink is ator rises above a threshold temperature than the processor 218 willcontinue to cause the backflow prevention current to be sourced to thePeltier modules 150.

The means by which the current is applied to the Peltier modules mayalso vary from what has been described. Thus, there is no requirementthat in all versions of the invention, a pulse width modulation systemis employed to regulate the actuation of the Peltier modules. In someversions of the invention, the current may be an always on current thatis regulated by regulating the voltage of the actuation signal.

In some versions of the invention, the structural members of the helmetor other article to which the cooling strip is mounted may be made fromthermally conductive material. The heat sunk to the heat sinks is drawninto these components. It should be recalled that these components arespaced away from the person wearing the personal protection unit. Thus,these components do not function as thermal conductors that simplyreturn heat to the person from which the heat was extracted. Thesecomponents function as heat sinks with added surface area over which theheat drawn away from the person wearing the personal protection systemof this invention is dispersed into the environment.

Accordingly, it is an object of the appended claims to cover all suchmodifications and variations that come within the true spirit and scopeof this invention.

What is claimed is:
 1. A surgical helmet system, said system comprising:a helmet comprising: a headband adapted to be worn around the head of anindividual; a module for manipulating the environment around the headthe individual; a first temperature sensor; a control processor incommunication with said first temperature sensor and said module; and agarment configured to be disposed over said helmet, said garmentcomprising a face shield configured to be positioned in front of theface of the individual; and wherein said control processor configured toreceive an input from said first temperature sensor and selectivelyenergize said module based on said input to manipulating the environmentaround the head the individual and covered by said garment.
 2. Thesystem of claim 1, wherein said module comprises one of a fan module ora thermoelectric cooling module.
 3. The system of claim 2, wherein saidfan module incudes a fan and is disposed above the headband, said fanconfigured to draw air through an overlaying section of said garment andaround the head of the individual wearing said system.
 4. The system ofclaim 2, further comprising a cooling strip mounted to the headband,said cooling strip including said thermoelectric cooling module; whereinsaid thermoelectric cooling module with a heat absorbing surface and aheat discharging surface.
 5. The system of claim 1, further comprising asecond temperature sensor configured to measure a characteristic of theenvironment around the head the individual; and wherein said controlprocessor is configured to receive an input from each of said firsttemperature sensor and said second temperature sensor and selectivelyenergize said module based on said input from at least one of said firsttemperature sensor and said second temperature sensor.
 6. The system ofclaim 5, further comprising a comparator configured to receive an inputfrom each of said second temperature sensor and a potentiometer, saidpotentiometer configured to be set to a user selected input based theenvironment around the head the individual; wherein said comparatorconfigured to output a signal based on said input from at least one ofsaid second temperature sensor and said potentiometer to said controlprocessor; and wherein said control processor is configured to receivesaid signal from said comparator and selectively energize said module.7. The system of claim 5, further comprising a battery in communicationwith said control processor and said module; and wherein said controlprocessor configured to selectively connect said battery to said moduleto energize said module based on said input from at least one of saidfirst temperature sensor and said second temperature sensor.
 8. Thesystem of claim 1, further comprising a battery in communication withsaid control processor and said module; and wherein said controlprocessor configured to selectively connect said battery to said moduleto energize said module based on said input from said first temperaturesensor.
 9. The system of claim 1, wherein said first temperature sensoris configured to measure a characteristic of said module.
 10. A methodof regulating a surgical helmet system including a helmet to be worn ona head of an individual and a garment including a face shield andconfigured to be disposed over the helmet, the helmet including a modulefor manipulating the environment around the head the individual wearingthe system, said method comprising: measuring a temperature with a firsttemperature sensor disposed on the helmet; providing a signal from thefirst temperature sensor to a control processor based on the measuredcharacteristic; and selectively energizing the module of the helmetbased on the signal from the first temperature sensor to manipulate theenvironment around the head the individual wearing the system.
 11. Themethod of claim 10, further comprising: setting a desired temperature ofthe individual wearing the system; measuring a temperature of theindividual wearing the system with a second temperature sensor;comparing the desired temperature of the individual with the measuredtemperature of the individual; selectively energizing the module of thehelmet to manipulate the environment around the head the individualwearing the system based on at least one of the temperature measure bythe first temperature sensor or a difference between the desiredtemperature of the individual with the measured temperature of theindividual.
 12. The method of claim 10, selectively energizing themodule of the helmet to manipulate the environment around the head theindividual wearing the system based on at least one of the temperaturemeasure by the first temperature sensor or a difference between adesired temperature of the individual with a measured temperature of theindividual.
 13. The method of claim 10, setting a desired temperature ofthe individual wearing the system; measuring a temperature of theindividual wearing the system with a second temperature sensor;comparing the desired temperature of the individual with the measuredtemperature of the individual; selectively energizing the module of thehelmet to manipulate the environment around the head the individualwearing the system for a time period that is proportional to thedifference between the desired temperature of the individual with themeasured temperature of the individual.
 14. The method of claim 10,wherein the module comprises at least one thermoelectric cooling moduleand further comprising the step of cyclically applying current to the atleast one thermoelectric cooling module until the at least onethermoelectric cooling module reaches a temperature at which thebackflow of any heat will not result in a rise in temperature of the atleast one thermoelectric cooling module that could possible result inthe discomforting heating of the individual wearing the system.
 15. Themethod of claim 10, wherein the module comprises a fan module and thestep of selectively energizing the module of the helmet furthercomprises rotating a fan of the fan module drawing air into a spaceunder the garment and around the head of the individual.
 16. A method ofregulating a surgical helmet system including a helmet to be worn on ahead of an individual and a garment including a face shield andconfigured to be disposed over the helmet, the helmet including a modulefor manipulating the environment around the head the individual wearingthe system, said method comprising: placing the garment over the helmetsuch the garment is secured to the helmet and the face shield is locatedforward of the helmet; activating the module; setting a desiredtemperature; measuring a temperature with a first temperature sensor;comparing the desired temperature to the measured temperature; providingan output representative of a difference between the desired temperatureand the measured temperature; and selectively energizing the module ofthe helmet based on the output.
 17. The method of claim 16, wherein saidstep of selectively energizing the module further comprises providing apulse to the module.
 18. The method of claim 17, wherein a time periodof the pulse is proportional to the difference between the desiredtemperature and the measured temperature.
 19. The method of claim 16,wherein the module comprises a fan module and the step of selectivelyenergizing the module of the helmet further comprises rotating a fan ofthe fan module drawing air into a space under the garment and around thehead of the individual.
 20. The method of claim 16, wherein the step ofmeasuring a temperature with a first temperature sensor comprisesmeasuring a temperature of the individual wearing the system.